<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Database schema utilities
*
* PHP version 5
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Database
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET')) {
exit(1);
}
/**
* Class representing the database schema
*
* A class representing the database schema. Can be used to
* manipulate the schema -- especially for plugins and upgrade
* utilities.
*
* @category Database
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
class MysqlSchema extends Schema
{
static $_single = null;
protected $conn = null;
/**
* Main public entry point. Use this to get
* the singleton object.
*
* @return Schema the (single) Schema object
*/
static function get()
{
if (empty(self::$_single)) {
self::$_single = new Schema();
}
return self::$_single;
}
/**
* Returns a TableDef object for the table
* in the schema with the given name.
*
* Throws an exception if the table is not found.
*
* @param string $table Name of the table to get
*
* @return TableDef tabledef for that table.
* @throws SchemaTableMissingException
*/
public function getTableDef($table)
{
$def = array();
$hasKeys = false;
// Pull column data from INFORMATION_SCHEMA
$columns = $this->fetchMetaInfo($table, 'COLUMNS', 'ORDINAL_POSITION');
if (count($columns) == 0) {
throw new SchemaTableMissingException("No such table: $table");
}
foreach ($columns as $row) {
$name = $row['COLUMN_NAME'];
$field = array();
// warning -- 'unsigned' attr on numbers isn't given in DATA_TYPE and friends.
// It is stuck in on COLUMN_TYPE though (eg 'bigint(20) unsigned')
list($type, $size) = $this->reverseMapType($row['DATA_TYPE']);
$field['type'] = $type;
if ($size !== null) {
$field['size'] = $size;
}
if ($type == 'char' || $type == 'varchar') {
if ($row['CHARACTER_MAXIMUM_LENGTH'] !== null) {
$field['length'] = intval($row['CHARACTER_MAXIMUM_LENGTH']);
}
}
if ($type == 'numeric') {
// Other int types may report these values, but they're irrelevant.
// Just ignore them!
if ($row['NUMERIC_PRECISION'] !== null) {
$field['precision'] = intval($row['NUMERIC_PRECISION']);
}
if ($row['NUMERIC_SCALE'] !== null) {
$field['scale'] = intval($row['NUMERIC_SCALE']);
}
}
if ($row['IS_NULLABLE'] == 'NO') {
$field['not null'] = true;
}
if ($row['COLUMN_DEFAULT'] !== null) {
$field['default'] = $row['COLUMN_DEFAULT'];
if ($this->isNumericType($type)) {
$field['default'] = intval($field['default']);
}
}
if ($row['COLUMN_KEY'] !== null) {
// We'll need to look up key info...
$hasKeys = true;
}
if ($row['COLUMN_COMMENT'] !== null && $row['COLUMN_COMMENT'] != '') {
$field['description'] = $row['COLUMN_COMMENT'];
}
$extra = $row['EXTRA'];
if ($extra) {
if (preg_match('/(^|\s)auto_increment(\s|$)/i', $extra)) {
$field['type'] = 'serial';
}
// $row['EXTRA'] may contain 'on update CURRENT_TIMESTAMP'
// ^ ...... how to specify?
}
if ($row['CHARACTER_SET_NAME'] !== null) {
// @fixme check against defaults?
//$def['charset'] = $row['CHARACTER_SET_NAME'];
//$def['collate'] = $row['COLLATION_NAME'];
}
$def['fields'][$name] = $field;
}
if ($hasKeys) {
// INFORMATION_SCHEMA's CONSTRAINTS and KEY_COLUMN_USAGE tables give
// good info on primary and unique keys but don't list ANY info on
// multi-value keys, which is lame-o. Sigh.
//
// Let's go old school and use SHOW INDEX :D
//
$keyInfo = $this->fetchIndexInfo($table);
$keys = array();
foreach ($keyInfo as $row) {
$name = $row['Key_name'];
$column = $row['Column_name'];
if (!isset($keys[$name])) {
$keys[$name] = array();
}
$keys[$name][] = $column;
if ($name == 'PRIMARY') {
$type = 'primary key';
} else if ($row['Non_unique'] == 0) {
$type = 'unique keys';
} else if ($row['Index_type'] == 'FULLTEXT') {
$type = 'fulltext indexes';
} else {
$type = 'indexes';
}
$keyTypes[$name] = $type;
}
foreach ($keyTypes as $name => $type) {
if ($type == 'primary key') {
// there can be only one
$def[$type] = $keys[$name];
} else {
$def[$type][$name] = $keys[$name];
}
}
}
return $def;
}
/**
* Pull the given table properties from INFORMATION_SCHEMA.
* Most of the good stuff is MySQL extensions.
*
* @return array
* @throws Exception if table info can't be looked up
*/
function getTableProperties($table, $props)
{
$data = $this->fetchMetaInfo($table, 'TABLES');
if ($data) {
return $data[0];
} else {
throw new SchemaTableMissingException("No such table: $table");
}
}
/**
* Pull some INFORMATION.SCHEMA data for the given table.
*
* @param string $table
* @return array of arrays
*/
function fetchMetaInfo($table, $infoTable, $orderBy=null)
{
$query = "SELECT * FROM INFORMATION_SCHEMA.%s " .
"WHERE TABLE_SCHEMA='%s' AND TABLE_NAME='%s'";
$schema = $this->conn->dsn['database'];
$sql = sprintf($query, $infoTable, $schema, $table);
if ($orderBy) {
$sql .= ' ORDER BY ' . $orderBy;
}
return $this->fetchQueryData($sql);
}
/**
* Pull 'SHOW INDEX' data for the given table.
*
* @param string $table
* @return array of arrays
*/
function fetchIndexInfo($table)
{
$query = "SHOW INDEX FROM `%s`";
$sql = sprintf($query, $table);
return $this->fetchQueryData($sql);
}
/**
* Close out a 'create table' SQL statement.
*
* @param array $sql
* @param string $name
* @param array $def
*/
function appendCreateTableEnd(array &$sql, $name, array $def)
{
$sql[] = ") ENGINE=InnoDB CHARACTER SET utf8 COLLATE utf8_bin";
}
/**
* Get the unique index key name for a given column on this table
*/
function _uniqueKey($tableName, $columnName)
{
return $this->_key($tableName, $columnName);
}
/**
* Get the index key name for a given column on this table
*/
function _key($tableName, $columnName)
{
return "{$tableName}_{$columnName}_idx";
}
/**
* Ensures that a table exists with the given
* name and the given column definitions.
*
* If the table does not yet exist, it will
* create the table. If it does exist, it will
* alter the table to match the column definitions.
*
* @param string $tableName name of the table
* @param array $columns array of ColumnDef
* objects for the table
*
* @return boolean success flag
*/
public function ensureTable($tableName, $columns)
{
// XXX: DB engine portability -> toilet
try {
$td = $this->getTableDef($tableName);
} catch (SchemaTableMissingException $e) {
return $this->createTable($tableName, $columns);
}
$cur = $this->_names($td->columns);
$new = $this->_names($columns);
$dropIndex = array();
$toadd = array_diff($new, $cur);
$todrop = array_diff($cur, $new);
$same = array_intersect($new, $cur);
$tomod = array();
$addIndex = array();
$tableProps = array();
foreach ($same as $m) {
$curCol = $this->_byName($td->columns, $m);
$newCol = $this->_byName($columns, $m);
if (!$newCol->equals($curCol)) {
$tomod[] = $newCol->name;
continue;
}
// Earlier versions may have accidentally left tables at default
// charsets which might be latin1 or other freakish things.
if ($this->_isString($curCol)) {
if ($curCol->charset != 'utf8') {
$tomod[] = $newCol->name;
continue;
}
}
}
// Find any indices we have to change...
$curIdx = $this->_indexList($td->columns);
$newIdx = $this->_indexList($columns);
if ($curIdx['primary'] != $newIdx['primary']) {
if ($curIdx['primary']) {
$dropIndex[] = 'drop primary key';
}
if ($newIdx['primary']) {
$keys = implode(',', $newIdx['primary']);
$addIndex[] = "add constraint primary key ($keys)";
}
}
$dropUnique = array_diff($curIdx['uniques'], $newIdx['uniques']);
$addUnique = array_diff($newIdx['uniques'], $curIdx['uniques']);
foreach ($dropUnique as $columnName) {
$dropIndex[] = 'drop key ' . $this->_uniqueKey($tableName, $columnName);
}
foreach ($addUnique as $columnName) {
$addIndex[] = 'add constraint unique key ' . $this->_uniqueKey($tableName, $columnName) . " ($columnName)";;
}
$dropMultiple = array_diff($curIdx['indices'], $newIdx['indices']);
$addMultiple = array_diff($newIdx['indices'], $curIdx['indices']);
foreach ($dropMultiple as $columnName) {
$dropIndex[] = 'drop key ' . $this->_key($tableName, $columnName);
}
foreach ($addMultiple as $columnName) {
$addIndex[] = 'add key ' . $this->_key($tableName, $columnName) . " ($columnName)";
}
// Check for table properties: make sure we're using a sane
// engine type and charset/collation.
// @fixme make the default engine configurable?
$oldProps = $this->getTableProperties($tableName, array('ENGINE', 'TABLE_COLLATION'));
if (strtolower($oldProps['ENGINE']) != 'innodb') {
$tableProps['ENGINE'] = 'InnoDB';
}
if (strtolower($oldProps['TABLE_COLLATION']) != 'utf8_bin') {
$tableProps['DEFAULT CHARSET'] = 'utf8';
$tableProps['COLLATE'] = 'utf8_bin';
}
if (count($dropIndex) + count($toadd) + count($todrop) + count($tomod) + count($addIndex) + count($tableProps) == 0) {
// nothing to do
return true;
}
// For efficiency, we want this all in one
// query, instead of using our methods.
$phrase = array();
foreach ($dropIndex as $indexSql) {
$phrase[] = $indexSql;
}
foreach ($toadd as $columnName) {
$cd = $this->_byName($columns, $columnName);
$phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd);
}
foreach ($todrop as $columnName) {
$phrase[] = 'DROP COLUMN ' . $columnName;
}
foreach ($tomod as $columnName) {
$cd = $this->_byName($columns, $columnName);
$phrase[] = 'MODIFY COLUMN ' . $this->_columnSql($cd);
}
foreach ($addIndex as $indexSql) {
$phrase[] = $indexSql;
}
foreach ($tableProps as $key => $val) {
$phrase[] = "$key=$val";
}
$sql = 'ALTER TABLE ' . $tableName . ' ' . implode(', ', $phrase);
common_log(LOG_DEBUG, __METHOD__ . ': ' . $sql);
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Is this column a string type?
*/
private function _isString(array $cd)
{
$strings = array('char', 'varchar', 'text');
return in_array(strtolower($cd['type']), $strings);
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param ColumnDef $cd column to create
*
* @return string correct SQL for that column
*/
function columnSql(array $cd)
{
$line = array();
$line[] = parent::columnSql($cd);
if ($cd['type'] == 'serial') {
$line[] = 'auto_increment';
}
if (!empty($cd['description'])) {
$line[] = 'comment';
$line[] = $this->quoteValue($cd['description']);
}
return implode(' ', $line);
}
function mapType($column)
{
$map = array('serial' => 'int',
'integer' => 'int',
'numeric' => 'decimal');
$type = $column['type'];
if (isset($map[$type])) {
$type = $map[$type];
}
if (!empty($column['size'])) {
$size = $column['size'];
if ($type == 'int' &&
in_array($size, array('tiny', 'small', 'medium', 'big'))) {
$type = $size . $type;
} else if (in_array($type, array('blob', 'text')) &&
in_array($size, array('tiny', 'medium', 'long'))) {
$type = $size . $type;
}
}
return $type;
}
/**
* Map a MySQL native type back to an independent type + size
*
* @param string $type
* @return array ($type, $size) -- $size may be null
*/
protected function reverseMapType($type)
{
$type = strtolower($type);
$map = array(
'decimal' => array('numeric', null),
'tinyint' => array('int', 'tiny'),
'smallint' => array('int', 'small'),
'mediumint' => array('int', 'medium'),
'bigint' => array('int', 'big'),
'tinyblob' => array('blob', 'tiny'),
'mediumblob' => array('blob', 'medium'),
'longblob' => array('blob', 'long'),
'tinytext' => array('text', 'tiny'),
'mediumtext' => array('text', 'medium'),
'longtext' => array('text', 'long'),
);
if (isset($map[$type])) {
return $map[$type];
} else {
return array($type, null);
}
}
function typeAndSize($column)
{
if ($column['type'] == 'enum') {
$vals = array_map(array($this, 'quote'), $column['enum']);
return 'enum(' . implode(',', $vals) . ')';
} else if ($this->_isString($column)) {
return parent::typeAndSize($column) . ' CHARSET utf8';
} else {
return parent::typeAndSize($column);
}
}
}